This invention generally relates to the field of footwear, and more particularly to athletic footwear. Specifically, the present invention relates to athletic footwear which incorporate at least one inflatable air bladder for adjusting the comfort and fit of the athletic footwear, and an apparatus for visually displaying the pressure within the inflatable air bladder.
In various types of athletic footwear, and in particular for footwear associated with particular types of athletic events, it is recognized that the comfort and fit of the footwear can affect the athletic performance. In order to increase both the comfort and fit of footwear, manufacturers have incorporated inflatable bladders of various designs into the construction of the footwear. The development, incorporation, and use of inflatable air bladders within athletic footwear was and is particularly appropriate for ski boots used for downhill skiing. Thus, a number of patents relate to the field of ski boots which incorporate inflatable air bladders, for example, German Patent No. 2,162,619, and more recently, U.S. Pat. No. 4,662,087. While the original designs for ski boots having air bladders incorporated the use of an external pressurizing device such as a hand pump, more recent designs incorporate the design of the pump into the article of footwear, such as for example the ski boot of U.S. Pat. No. 4,702,022.
The demands for comfort and snugness of fit in other athletic events has resulted in the use of the inflatable bladders originally developed for ski boots in various types of athletic footwear, including athletic shoes used for basketball and other sports. There are presently available athletic shoes incorporating an air pump, such as depicted within U.S. Pat. No. 5,074,765, to inflate air bladders located within the sole of the shoe, or alternatively, bladders located in portions of the upper or the tongue of the athletic shoe. The advantages of these types of shoes is manifested primarily by their increased comfort and the secure positioning or fit of the foot within the shoe. Another benefit derived from the use of air bladders is the potential for reduction of forces transmitted through the shoe to the foot and ankle of the wearer during performance of the athletic endeavor. Thus, current athletic shoes having incorporated air bladders provide enhanced comfort and fit, while also reducing the occurrence of various types of injuries.
For the athletic shoes currently available which incorporate both the inflatable air bladders and a pump inflation means, the comfort and fit of the article of footwear is adjusted by inflating the air bladder by use of the pump after securing the footwear about the foot. The wearer simply inflates the air bladder until a particular pressure level, or fit, is felt by the foot. However, due to the rigors of various athletic events, and because the human foot tends to swell and contract with varying levels of activity, it is very difficult for the individual to obtain a consistent fit from one use to the next, or to recognize the difference in their performance, based upon a pressure setting for the air bladders that is merely sensed by the foot. This problem is primarily related to the fact that there is no currently available means for indicating the particular pressure to which the user has inflated the air bladder. Thus, it would be beneficial to have a means for indicating the pressure within the air bladder, thereby indicating the particular fit which is most advantageous for enhanced performance. A visual reference to which the user may refer when first affixing the shoe to the foot, prior to a particular athletic use, or alternatively, during use, when it may be desirable to vary or restore a given fit, is therefore desirable.
Accordingly, the present invention is directed to an article of athletic footwear which incorporates inflatable air bladders, and which also includes a pressure sensing means and means for displaying the sensed pressure in the air bladders.